1. Field of the Invention
Embodiments of the invention relate generally to the field of communication systems. More particularly, an embodiment of the invention relates to navigation systems, and methods of performing navigation.
2. Discussion of the Related Art
Prior art navigation systems, such as the Global Positioning System (GPS), are known to those skilled in the art. For instance, a conventional global positioning system consists of more than two dozen GPS satellites broadcasting precise timing signals by radio to GPS receivers, allowing them to accurately determine their location (longitude, latitude, and altitude) anywhere on Earth.
A problem with this technology has been the lack of reliability in thick foliage, rough terrain, and urban areas. Therefore, what is required is a solution that provides navigation systems able to reliably function under such conditions.
Another problem with this technology has been the long time required to obtain a new fix, as well as susceptibility to multipath effects, jamming, or spoofing signals. Therefore, what is also required is a solution that provides a quicker and more robust fix, able to detect multipath, jamming or spoofing induced errors.
One unsatisfactory approach, in an attempt to solve the above-discussed problems involves the use of narrow correlator spacing to reduce noise and multipath effects. However, a disadvantage of this approach is that it does not substantially improve time-to-first-fix, nor does it improve reliability in areas where GPS signals cannot penetrate.
Heretofore, the requirements of reliable signals in difficult terrain, quick time-to-first-fix, and robustness of the fix referred to above have not been fully met. What is needed is a solution that simultaneously solves this all of these problems.